Hermetic compressors having horizontal crankshafts



R. W. AYLING March '5, 1963 HERMETIC COMPRESSORS HAVING HORIZONTALCRANKSHAFTS Filed May 22, 1962 United rates i atent 3,030,166 HERMETICCOMPRESSORS HAVING HQRIZQNTAL CRANKSHAFTS Robert W. Ayling, Staunton,Va., assignor to Westinghouse Electric Qorporation, East Pittsburgh,Pin, a

corporation of Pennsylvania Filed May 22, 1962, Ser. No. 6,819 7 Claims.(Cl. lid-4.06)

This invention relates to refrigerant compressors, and relates moreparticularly to hermetic compressors having horizontal crankshaftsconnected to electric driving motors.

In refrigerant compressors having horizontal crankshafts, it isdesirable to maintain the crankcase oil charge while maintaining themotor compartment essentially dry. This assures an adequate supply ofoil for the lubricating pump located in the crankcase, and prevents oilfrom building up in the motor compartment to the level of the motorrotor and causing increased power requirements and excessive oilcirculation. During normal operation, blowby past the piston rings ofthe compressor tends to pressurize the crankcase and inhibit oil return,resulting in high oil circulation and decreased heat transfer in therefrigeration system in which the compressor is connected. During aflooded start, the churning of the oil-refrigerant mixture promotes oilloss in the system at the time lubricant is most needed.

An object of this invention is to maintain a high oil level in thecrankcase of a hermetic, motor driven compressor, and to maintain themotor compartment of the compressor essentially dry.

Another object of this invention is to reduce the loss of oil to arefrigeration system in which a refrigerrant compressor is connected,during flooded starts of the com-.

pressor. 1

This invention will now be described with reference to the annexeddrawings, of which:

FIG. 1 is a fragmentary cross section of a hermetic compressor embodyingthis invention, and

FIG. 2 is an enlarged fragmentary view of the outer end of the motorrotor of FIG. 1.

Referring now to the drawings, a refrigerant compressor has a horizontalcrankshaft having an inner portion 10 with a throw 11 for a connectingrod of a piston which is not shown, in a crankcase compartment 12. Thecrank shaft portion extends through spaced-apart bearings 13 in abearing housing 14 into motor compartment 15. The housing 14 issupported by partition 16 from casing 17 of the compressor, and with thepartition 16 separates the crankcase compartment 12 from the motorcompartment 15. The outer ends of the crankshaft portion 10, the outerbearing 13 and the housing 14 extend almost to the center of quill 18 ofelectric motor rotor 19. The crankshaft has an outer portion 20 ofreduced diameter, the outer end of which extends almost to the outer endof the quill 18, and has a shoulder 21 where its inner portion 10 andouter portion 20 join.

The inner surface of the outer portion of the quill 18 contacts theouter portion 20 of the crankshaft and is attached thereto for rotationtherewith. The bearing housing 14 has a cylindrical portion 22 whichextends within the quill 18 almost to the outer crankshaft portion 20,the inner portion of the quill having a very small clearance passage 23around the inner portion of the hous ing portion 22, forming anelfective seal. A seal ring could be used in which case the passage 23could be larger. The housing portion 22 has an outer end portion 24 witha reduced diameter. A passage 25 larger than the seal passage 23 isformed between the housing portion 24 and the adjacent quill surface.The quill 18 has a vertically extending shoulder 27 spaced outwardlyfrom the outer end of the housing portion 24 and forming therewith avertically extending passage 30 which connects at its periphery with thepassage 25. The housing 14 has a horizontally extending, upper hole 32therein, the inner end of which connects through an opening 3?: in thehousing 14 with the crankcase compartment 12, and the outer end of whichconnects with the passage 39. The housing 14 has a lower, horizontallyextending, circular hole 34 therein, the inner end of which connectsthrough an opening 35 in the housing 14 with the crankcase compartment12, and the outer end of which contains a plug 36. The bottom of thepassage 25 connects through a hole 37 in the housing portion 24 with thehole 34.

A circular rotor retaining plate 43 is attached to the rotor quill 18 bymachine screws 49. A smaller, rectangular rotor lock plate at is incontact with the central portion of the outer surface of the plate 43. Abolt 4 extends through the plates 40 and i3 and is threaded into theouter end of the shaft portion 20.

The outer end of the crankshaft portion 2t} terminates slightly short ofthe outer end of the quill l8, and the central portion of the outer endof the quill is recessed, the recess so formed and the space between theouter end of the crankshaft portion 26 and the inner surface of theplate 43 forming a vertically extending passage 42. The outer portion ofthe quill 18 around the crankshaft por tion 2% has a pair ofdiametrically opposite holes 33 and 39 therein, the inner ends of whichopen into the passage Eli, and the outer ends of which open into thepassage 42. The holes 38 and 39 converge towards their outer ends. Theplate 4-3 has extending therethrough a pair of diametrically opposite,inwardly slanted holes 45 and 46, the inner ends of which open into thepassage 42. The holes 45 and 46 contain the inner ends of gas pumpingtubes 47 and 48 respectively, the outer portionsof which extendradially, and the outer ends of which open into the motor compartment15. The inner ends of the holes 45 and 46 are nearer the axis of thecrankshaft than are the outer ends of the holes 38 and 39 so thatcentrifugal force can prevent oil in the holes 38 and 39 from enteringthe holes 45 and 46.

There is a conventional stator 52 with a coil 53 around the rotor 19.The outer end of the casing 17 has a cap 55 with a suction gasconnection 56. The upper portion of the casing 17 has near the inner endof the motor compartment a passage 58 for connecting the motorcompartment with the suction sides of the compressor cylinders which arenot shown. The lower portion of the partition 16 has check valve 60therein for permitting oil flow from the motor compartment into thecrankcase compart ment, and for preventing flow in the reversedirection.

Operation in operation, rotation of the gas pumping tubes 47 and 48 bythe rotor 19, through well known centrifugal fan action, reducespressure within the crankcase compartment 12 by applying suction throughthe holes 45 and 46, the passage 42, the holes 3% and 39, the passage30, the holes 32 and 34 and the openings 33, 35 and 37 so that thepressure within the crankcase compartment 12 is lower than it is in themotor compartment 15. The mixed gas and oil from the crankcasecompartment 12 passes through the upper hole 32 into the passage 30Where initial oil separation takes place as a result of centrifugalforce. Oil pressure builds up in the passage 25 and causes the separatedoil to fiow from the bottom of the passage 25 through the opening 37into the hole 34 and through the opening 35 back into the crankcasecompartment. Further separation of any oil which passes into the holes38 and 39 in the rotor quill 18 takes place in these holes. Due to therotation of the quill, any oil in the holes 38 and 39 is thrown bycentrifugal force from passing into the holes :5 and 4d.

against the surfaces of the quill around the holes and flows through theholes back into the passage 39, this flow being aided by the slope ofthe holes towards the passage 30 when the holes are in their lowermostpositions. This .Oil flows from the passage 30 back into the crankcasecompartment along with the oil separated in the initial separation. v

The holes 38 and 39 preferably are displaced circumferentially from theholes 45 and 46 respectively, as shown at 38A and 39A on FIG. 2, forproviding increased centrifugal separation.

When the compressor is shut down, oil that has accumulated in theannular passage 25 drains through the opening 37, hole 34 and opening 35into the crankcase compartment.

The refrigerant gas from which all oil is separated passes out the tubesd7 and 4%; into the motor compartment 215, this flow being from theouter ends of the tubes 38 and 39 into the passage 42 and from thelatter through the holes 45 and as into the tubes 4?? and 4srespectively. Since the outer ends of the holes 38 and 39' are spacedfurther from the axis of the crankshaft than are the inner ends of theholes 45 and i6, centrifugal force prevents any oil It should beapparent that the centrifugal forces acting on the oil that is separatedfrom the gas are greater than theforce resulting from the pressuredifference between the crankcase and motor compartments.

V The flow through the holes 32 and 34 in the bearing housing 14elfectively cools the bearings 13. Since such holes are not in thecrankshaft, the latter is not weakened.

The machine screws 49 not only serve to attach the plate 43 to the rotorquill 13 but they, the plate 43 and the bolt 41 provide a convenientmeans for jacking the rotor off the crankshaft, eliminating thenecessity for the previously used wheel puller. By removing the screws49, the bolt 41 and the plate 43, reinserting the bolt 41 in thecrankshaft, placing the plate 43 against the outer end of the bolt 41,reinserting the screws 49' through the plate 43 into the quill l8, andtightening the screws 49, the rotor can he pulled off the crankshaft.

What is claimed, is:

1. In a hermetic compressor-motor unit having a crankcase compartment, amotor compartment horizontally aligned wtih said compartment, meansincluding a bearing housing forming a partition between saidcompartments, said housing having an outer cylindrical portion extendinginto said motor compartment, said unit having a crankshaft bearing insaid housing, having a check valve in said partition, and having a motorin said motor compartment,

- the combination of a horizontal crankshaft having an innerportionwithin said bearing and extending into said compartments andhaving an outer portion within said motor compartment, said housinghaving upper and lower holes therein above and below respectively, saidinner crankshaft portion and connecting at their inner ends with saidcrankcase compartment, said motor having a rotor quill having an outerportion around and attached to said outer crankshaft portion and havingan inner portion around and spaced from said outer housing portion, theouter end portion of said housing having a reduced diameter and formingwith said inner quill portion an annular passage around the outer endsof said holes, said quill having an intermediate portion with avertically extending surface spaced from and forming with the outer endof said housing a passage connecting with said annular passage and saidupper hole and connecting through said annular passage with said lowerhole, and gas pumping means connected to said quill for rotation withsaid quill, said pumping means having a gas inlet connected to saidpassage connecting with said annular passage and having a gas outlet insaid motor compartment.

2. In a hermetic compressor-motor unit having a crankcase compartment, amotor compartment horizontally aligned with said compartment, meansincluding a bearing housing forming a partition between saidcompartments, said housing having an outer cylindrical portion extendinginto said motor compartment, said unit having a crankshaft bearing insaid housing, having a check valve in said partition, and having a motorin said motor compartment, the combination of a horizontal crankshafthaving an inner portion within said bearing and extending into saidcompartments and having an outer portion within said motor compartment,said housing having upper and lower holes therein above and belowrespectively, said inner crankshaft portion and connecting at theirinner ends with said crankcase compartment, said motor having a rotorquill havingan outer portion around and attached to said outercrankshaft portion and having an inner portion around and spaced fromsaid outer housing portion, the outer end portion of said housing havinga reduced diameter and forming with said inner quill portion an annularpassage around the outer ends or" said holes, said quill having anintermediate portion with a vertically extending surface spaced from andforming with the outer end of said housing a vertically extendingpassage connecting with said annular passage and the outer end of saidupper hole and connecting through said annular passage with said lowerhole, said outer portion of said quill having diametrically oppositeholes therein connecting at their inner ends with said verticallyextending passage, the outer end of said quill having alrecess withwhich the outer ends of said last mentioned holes connect, a rotorlocking plate extending across said outer end of said quill and saidrecess, and gas pumping means attached to said plate and having a gasinlet connecting with said recess and spaced closer to the axis of saidcrankshaft than said last mentioned hole ends and having a gas outletdischarging into said motor compartment, said gas outlet being spacedfurther from said axis than said gas inlet.

3. in a hermetic compressor-motor unit having a crankcase compartment, amotor compartment horizontally aligned with said compartment, meansincluding a hearing housing forming a partition between saidcompartments, said housing having an outer cylindrical portioncxtendinginto said motor compartment, said unit having a crankshaft bearing insaid housing, having a check valve in said partition, and having a motorin said motor compartment, the combination of a honizontal crankshafthaving an inner portion within said bearing and extending into saidcompartments and having an outer portion within said motor compartment,saidihousing having therein upper and lower holes above and belowrespectively, said inner crankshaft portion and connecting at theirinner ends with said crankcase compartment, said motor having a rotorquill having an outer portion around and attached to said outercrankshaft portion and having an inner portion around and spacedfromsaid outer housing portion, the outer end portion of said housing havinga reduced diameter and forming with said inner quill portion an annularpassage around the outer ends of said holes, said quill having anintermediate portion with a vertically extending surface spaced from andforming with the outer end of said housing a vertically extendingpassage connecting with said annular passage and the outer end of saidupper hole and connecting through said annular passage with the outerend of said lower hole, said outer portion of said quill havingdiametrically opposite holes therein connecting at their inner ends withsaid vertically extending passage, means forming a passage at the outerend of said quill connecting with the outer ends of said last mentionedholes, and gas pumping means connected to said quill for rotationtherewith, said pumping means having an inlet connecting with said lastmentioned passage closer to the axis of said crankshaft than said lastmentioned hole ends, and having an outlet further from said'axis thansaid inlet.

4. In a hermetic compressor-motor unit having a crankcase compartment, amotor compartment horizontally aligned with said compartment, meansincluding a bearing housing forming a partition between saidcompartments,

said housing having an outer cylindrical portion extending into saidmotor compartment, said unit having a crankshaft bearing in saidhousing, having a check valve in said partition, and having a motor insaid motor compartment, the combination of a horizontal crankshafthaving an inner portion within said bearing and extending into saidcompartments and having an outer portion within said motor compartment,said housing having therein upper and lower holes above and belowrespectively, said inner crankshaft portion and having inner endsconnecting with said crankcase compartment, said motor having a rotorquill having an outer portion around and attached to said outercrankshaft portion and having an inner portion around and spaced fromsaid outer housing portion, the outer end portion of said housing havinga reduced diameter and forming with said inner quill portion an annularpassage around the outer ends of said holes, said quill having anintermediate portion with a vertically extending surface spaced from andforming with the outer end of said housing a vertically extendingpassage connecting with said annular passage and the outer end of saidupper hole and connecting through said annular passage with the outerend of said lower hole, said outer portion of said quill havingdiametrically opposite holes therein connecting at their inner ends withsaid vertically extending passage and converging towards the outer endof said quill, means forming a passage at said outer end of said quillconnecting with the outer ends of said last mentioned holes, and gaspumping means connected to said quill for rotation therewith, saidpumping means having an inlet connecting with said last mentionedpassage closer to the axis of said crankshaft than said last mentionedhole ends, and having an outlet further from said axis than said inlet.

5. In a hermetic compressonmotor unit having a crankcase compartment, amotor compartment horizontally aligned with said compartment, meansincluding a bearing housing forming a partition between saidcompartments, said housing having an outer cylindrical portion extendinginto said motor compartment, said unit having a crankshaft bearing insaid housing, having a check valve in said partition, and having a motorin said motor compartment, the combination of a horizontal crankshafthaving an inner portion Within said bearing and extending into saidcompartments and having an outer portion in said motor compartment, saidhousing having therein upper and lower holes above and belowrespectively, said inner crankshaft portion and having inner endsconnecting with said crankcase compartment, said motor having a rotorquill having an outer portion around and attached to said outercrankshaft portion and having an inner portion around and spaced fromsaid outer housing portion, the outer end portion of said housing havinga reduced diameter and forming with said inner quill portion an annularpassage around the outer ends of said holes, said quill having anintermediate portion with a vertically extending surface spaced from andforming with the outer end of said housing a vertically extendingpassage connecting with said annular passage and the outer end of saidupper hole, said housing having an opening connecting the bottom of saidannular passage with the outer end of said lower hole, and gas pumpingmeans connected to said quill for rotation therewith and having a gasinlet connected to said vertically extending passage and having a gasoutlet discharging into said motor compartment.

6. In a hermetic compressor-motor unit having a crankcase compartment, amotor compartment horizontally aligned with said compartment, meansincluding a hearing housing forming a partition between saidcompartments, said housing having an outer cylindrical portion extendinginto said motor compartment, said unit having a crankshaft bearing insaid housing, having a check valve in said partition, and having a motorin said motor compartment, the combination of a horizontal crankshafthaving an inner portion within said bearing and extending into saidcompartments and having an outer portion Within said motor compartment,said housing having therein upper and lower holes above and belowrespectively, said inner crankshaft portion and connecting at theirinner ends with said crankcase compartment, said motor having a rotorquill having an outer portion around and attached to said outercrankshaft portion and having an inner portion around and spaced fromsaid outer housing portion, the outer end of said housing having areduced diameter and forming with said inner quill portion an annularpassage around the outer ends of said holes, said quill having anintermediate portion with a vertically extending surface spaced from andforming with the outer end of said housing a vertically extendingpassage connecting with said annular passage and the outer end of saidupper hole, said housing having an opening connecting the bottom of saidannular passage with the outer end of said lower hole, said outer quillportion having diametrically opposite holes therein connecting at theirinner ends with said vertically extending passage, means forming apassage at the outer end of said quill connecting with the outer ends ofsaid last mentioned holes, and gas pumping means connected to said quillfor rotation therewith, said pumping means having an inlet connectingwith said last mentioned passage closer to the axis of said crankshaftthan said last mentioned hole ends, and having an outlet further fromsaid axis than said inlet.

7. In a hermetic compressor-motor unit having a crankcase compartment, amotor compartment horizontally aligned with said compartment, meansincluding a bearing housing forming a partition between saidcompartments, said housing having an outer cylindrical portion extendinginto said motor compartment, said unit having a crankshaft hearing insaid housing, having a check valve in said partition, and having a motorin said motor compartment, the combination of a horizontal crankshafthaving an inner portion Within said bearing and extending into saidcompartments and having an outer portion within said motor compartment,said housing having therein upper and lower holes above and belowrespectively, said inner crankshaft portion and connecting at theirinner ends with said crankcase compartment, said motor having a rotorwith a rotor quill having an outer portion around and attached to saidouter crankshaft portion and having an inner portion around and spacedfrom said outer housing portion, the outer end of said housing having areduced diameter and forming with said inner quill portion an annularpassage around the outer ends of said holes, said quill having anintermediate portion with a vertically extending surface spaced from andforming with the outer end of said housing a vertically extendingpassage connecting with said annular passage and with the outer end ofsaid upper hole, said housing having an opening connecting the bottom ofsaid annular passage with the outer end of said lower hole, said outerquill portion having diametrically opposite holes therein connecting attheir inner ends with said vertically extending passage and convergingtowards the outer end of said quill, means forming a passage at saidouter end of said quill connecting with the outer ends of said lastmentioned holes, and gas pumping means connected to said quill forrotation therewith, said pumping means having an inlet connecting withsaid last mentioned passage closer to the axis of said crankshaft thansaid last mentioned hole ends, and having an outlet further from saidaxis than said inlet.

No references cited.

4. IN A HERMETIC COMPRESSOR-MOTOR UNIT HAVING A CRANKCASE COMPARTMENT, AMOTOR COMPARTMENT HORIZONTALLY ALIGNED WITH SAID COMPARTMENT, MEANSINCLUDING A BEARING HOUSING FORMING A PARTITION BETWEEN SAIDCOMPARTMENTS, SAID HOUSING HAVING AN OUTER CYLINDRICAL PORTION EXTENDINGINTO SAID MOTOR COMPARTMENT, SAID UNIT HAVING A CRANKSHAFT BEARING INSAID HOUSING, HAVING A CHECK VALVE IN SAID PARTITION, AND HAVING A MOTORIN SAID MOTOR COMPARTMENT, THE COMBINATION OF A HORIZONTAL CRANKSHAFTHAVING AN INNER PORTION WITHIN SAID BEARING AND EXTENDING INTO SAIDCOMPARTMENTS AND HAVING AN OUTER PORTION WITHIN SAID MOTOR COMPARTMENT,SAID HOUSING HAVING THEREIN UPPER AND LOWER HOLES ABOVE AND BELOWRESPECTIVELY, SAID INNER CRANKSHAFT PORTION AND HAVING INNER ENDSCONNECTING WITH SAID CRANKCASE COMPARTMENT, SAID MOTOR HAVING A ROTORQUILL HAVING AN OUTER PORTION AROUND AND ATTACHED TO SAID OUTERCRANKSHAFT PORTION AND HAVING AN INNER PORTION AROUND AND SPACED FROMSAID OUTER HOUSING PORTION, THE OUTER END PORTION OF SAID HOUSING HAVINGA REDUCED DIAMETER AND FORMING WITH SAID INNER QUILL PORTION AN ANNULARPASSAGE AROUND THE OUTER ENDS OF SAID HOLES, SAID QUILL HAVING ANINTERMEDIATE PORTION WITH A VERTICALLY EXTENDING SURFACE SPACED FROM ANDFORMING WITH THE OUTER END OF SAID HOUSING A VERTICALLY EXTENDINGPASSAGE CONNECTING WITH SAID ANNULAR PASSAGE AND THE OUTER END OF SAIDUPPER HOLE AND CONNECTING THROUGH SAID ANNULAR PASSAGE WITH THE OUTEREND OF SAID LOWER HOLE, SAID OUTER PORTION OF SAID QUILL HAVINGDIAMETRICALLY OPPOSITE HOLES THEREIN CONNECTING AT THEIR INNER ENDS WITHSAID VERTICALLY EXTENDING PASSAGE AND CONVERGING TOWARDS THE OUTER ENDOF SAID QUILL, MEANS FORMING A PASSAGE AT SAID OUTER END OF SAID QUILLCONNECTING WITH THE OUTER ENDS OF SAID LAST MENTIONED HOLES, AND GASPUMPING MEANS CONNECTED TO SAID QUILL FOR ROTATION THEREWITH, SAIDPUMPING MEANS HAVING AN INLET CONNECTING WITH SAID LAST MENTIONEDPASSAGE CLOSER TO THE AXIS OF SAID CRANKSHAFT THAN SAID LAST MENTIONEDHOLE ENDS, AND HAVING AN OUTLET FURTHER FROM SAID AXIS THAN SAID INLET.